Inclusion Criteria:

   - Histologically confirmed diagnosis of recurrent PVNS ( or diffuse-type giant cell
   tumor or tenosynovial giant cell tumor) that is unresectable, metastatic, or for which
   the patient refuses surgical intervention

   - Progressive disease in the last 12 months, as demonstrated by imaging or clinical
   appearance of new tumors, in the opinion of the treating investigator

   - At least one site of measurable disease according to RECIST 1.1 on MRI (or CT scan for
   metastatic disease)

   - Any number or type of prior systemic therapies, with the exception of known or
   suspected CSF1 receptor inhibitors as outlined in exclusion criteria below

   - 18 years of age or older

   - Life expectancy greater than 6 months

   - ECOG Performance Status of 0, 1 or 2

   - Normal organ and marrow function as defined in the protocol

   - QTc less than or equal to 450 ms on 12-lead ECG

   - Negative urine or serum pregnancy test within days of start of study drug
   administration for women of childbearing potential.

   - Women of childbearing potential and men must agree to use adequate contraception prior
   to study entry, for the duration of study participation, and for 3 months following
   study drug discontinuation

Exclusion Criteria:

   - Prior treatment with known or suspected CSF1 receptor inhibitor, including nilotinib,
   imatinib, sunitinib, or sorafenib, or other approved or investigational tyrosine
   kinase inhibitors used for treatment of diffuse-type giant cell tumor

   - Concurrent treatment with other investigational agents

   - Inability to tolerate or contraindication to MRI scanning for participants with
   localized disease

   - Impaired cardiac function

   - Current treatment with strong CYP3A4 inhibitors that cannot either be discontinued or
   switched to a different medication prior to starting study drug

   - Current treatment with any medications that have the potential to prolong the QT
   interval and that cannot either be discontinued or switched to a different medication
   prior to starting study drug

   - Impaired gastrointestinal (GI) function or GI disease that may significantly alter the
   absorption of study drug

   - Acute or chronic pancreatic disease

   - Acute or chronic liver disease

   - Another primary malignant disease requiring systemic treatment or radiation

   - History of significant congenital or acquired bleeding disorder unrelated to cancer

   - Major surgery within 28 days prior to Day 1 of the study

   - Treatment with other investigational agents within 28 days of day 1

   - History of non-compliance to medical regimens or inability to grant consent

   - Women who are pregnant or breastfeeding

   - Other comorbidities that would interfere with study participation or safety in the
   opinion of the investigator